Refractory article



Sept. 1931. R, FRINK 1,823,356

REFRACTORY ARTICLE Filed Nov. 2o, 1926 INVENTO'R.

5015er/ 0C. frz-Wk. gag. M @W ATTORNEYS.

Patented Sept. 15,y 1931 l UNITED STATES PATENT oFFlcE f ROBERT L.4FRINK, OF LANCASTER, OHIO .REFRAGTOBY ARTICLE Lppneation mea Novemberao, 192s. serial No. 149,604.

This invention relates to refractories, and more particularly suchmaterial as is of a character adaptabletb desired` shapes or tocontinuous linings. Heretofore great diiii# culty has been experienced-in ,obtaining materialgwhich would withstand the imposed temperaturesand at thesametime eiiect suiiicient heat insulation as vto bepractical, particularly where very high temperatures are employed. Amongthe objects of the present invention are the provision of an improvedrefractory, and methods that arepractical and effective, which may beemployed yin connection with the preparation of refractory units orlarticles or with new installation or with repair of existentinstallation.

To the s accomplishment of the foregoing and related ends, theinvention, then, con-r and particularly pointedout in the claim, the

following description and the annexed drawing setting forth indetail butone of thevarious methods in which the principle of the invention may beused. i

In said annexed drawing The sole :ligure represents a section through abody of material in accordance'with the.

l present invention.

l Heretofore there have been numerous attempts to make a refractoryshape in a sort Vof integral mass. by using as a base ordinary fire-clayand surfacing this with more refractory materials, such as bauxite,etc.- but on account of the disproportionate shrinkage in drying andfiring, and the different coeilicient of expansion and contraction ofthe respectivecomponents, successful results have not been' attained.V

With the present invention, an exposed surface of desired density andrefractory character maybe had, and -with `a body 'of differingporosity, but all of a coefficient of'expansion such -as to avoiddisruptive stresses.

The reference character 1` in the drawing designates the face orsuriicial portion of a refractory, and such portion may be of very densecharacter. .The body is of relatively greater porosity,and this maycomprise zones of graduated character, for instance the referencenumeral 2 designates an intermediate sists in the ,features hereinafterdescribed,l

zone in which the porosity is more prominent, and the zone or portion 3is characterized by still greater porosity. Instead of having sharplydemarked zones, I also contemplate gradating or shading off the extentof porosity from a surficial portion to the back portion of thematerial. In forming such material, I prefer to employ a compositioncontaining silica, boron compounds, alkaline earths, and alkalies, and lmay include more or less highly refractory substances such assillimanite, mullite, thoria,

or zirconia, and other rare earths. yAs an illustration, an effectivecomposition may be made up of ignited silica about 4() parts, fused 65or anhydrous boric acid about 20 parts, ig-A nited thorium oxide about15 parts, ignited zirconium oxide about 15 parts, sodium chlorideabout'2 parts, and magnesium chloride about S'parts, all by weight.These constitu- 7 ents are -preferably ground to fine mesh, for instancel/lOOths inch or finer and ten parts of this may then be mixed with 90parts of sillimanite or the like, in graded and sized particles. Wateris added to make the mass sufficiently plastic for molding, and this maythen be formed into the shape desired, either as a unit or shapedarticle or as a mass applied to a wallto be repaired or lined or as maybe required. Whatever the refractory material employed, my inventioncontemplates providing more or less porosity either gradatedor zoned asdesired, and such porosity may be attained by admixing for the desiredportions amounts of granular or the like material destructible at thetemperatures to which the refractory will be subsequently subjected. Asexamples of feasible materials for this purpose, there may be employedsawdust or particles of wax or rosin etc., the destructible or fugitiveparticles being mixed in to the refractory mass for those portionsintended to be porous and in relative amounts as determined thereby. Anadvantageous way of handling the material is to apply itby means of acement gun, such as is commonly usedfor applyingstucco or cement; andwith the material in a suitable state of plasticity, it may thus bethrown into position in the form to be built up, Whether 10Q form, anintegral wall may be built up 'irry vsuch general manner, and thesuccessive portions as ap lied may be varied as tostheir' content ofugitive particles added; similarly in the case of a mold for units. orblock shapes to be produced. -The refractory material for instance maybe applied to the supporting surface or form'initially Without ancontent of the fugitive particles until a su ficient surlicial portionhas been built up, and then the fugitive or destructible particles maybe introduced into the mass as it is being applied, and the proportionof such particlesmay be progressively increased as the building upin'thickness proceeds, suchthat the greatest proportion of thedestructible particles will occur in the final portion or layer.Progressively if desired, the greatest proportion of destructibleparticles may be lntroduced in the material as first applied andtheproportion of such particles may be 2'5 then progressively diminished tothe surlicial.

portion which may be applied entirely free of such destructibleparticles. Instead of progressively increasing or diminishing theproportion of fugitivel particles as a plied, I

may of course vay the proportion y sharp-V ly divided stages orl layers,all as may be preferred. g

With the material in place, either in the form of a wall lor in a-moldas the case may be, it is then allowed to dry to a condition suitablefor ring. The temperature of firing is such as to destroy the fugitiveparticles .f

in the refractory mass and leave in place of such particles voids orporosities. The tem- 40 perature to which the refractory material israised will desirably besuch as to 4just fuse the lessrefractorymaterial and allow consequent physical and chemical chan es or as theentire operation may be term set the .45 material', care being taken ofcourse that voids as provided by the destruction o'f the fugitiveyparticles be not obliterated by complete flowage of the refractorymaterial to densification. After this treatment, it is desirable .50especially for shaped pieces or units to again heat in order to give anadded finish to the surface. If the refractory material being used iscompound silicate of boron, etc. with sillimanite or the like, asinstanced above,

jf/'''this temperature may. desirably be 1450 C.

-to 1550 C. or above.- S/uch heating increases the fugitive particlesIand the heating treatment lnstanced. In any case however, it will-thusbe seen-that porosityto any desired extent may be provided in the bodyof a refractory and the surlicial portions may be of -a density entirelydifferent. This allows of.

adaptation of materials for various conditions of usage, and in suchmanner I am enabled to produce refractory shapes of a very superiorquality.'

The y. magnesium' oxide and magnesium chloride provide the elements foran oxy-v chloride cemet whichyis effective for binding the materialstogether, at low tempera-- This the invention may be employed, changebeing made in the particular details disclosed, provided t-he steps orstructure stated in kany of the'following claim or the equivalent ofsuch be employed.

I therefore particularly point out and distinctly claimas my invention.As'a new article of manufacture, a body of material adapted towithstand high furnace temperatures, the body having a face portionwhich is dense and continuous in character and having anintegral'bodyextending continuously behind said dense face portion, thebody being porous and the porosity ofthe body increasing toward the facethereof opposite said dense face portion.

v ASigned by me this 30 day of October, 1926.

ROBERT L. FRINK.

the density of the surface to a depth which I depend upon. the durationof treatment and the precise temperature employed.

A 60 Instead of applying the surlicial portion in i I a plastic orliuent cold statel as above described, I also contemplate in someinstances applying the material ina fused condition so as toA therebyform a facing on-a. porous mass l '65 or block previously produced bythe use of iso

